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authorjmcneill <jmcneill@NetBSD.org>2018-10-15 11:33:09 +0000
committerjmcneill <jmcneill@NetBSD.org>2018-10-15 11:33:09 +0000
commita43b0fb9ea8aa46c45e42fb0b101ce2c05b4e2ce (patch)
treefdbcb904b11b162b74038637396c8a01d163a96e /sys/dev/acpi/acpi_timer.c
parent7970a7c95d8caa841334016f93685caba1eacd49 (diff)
Do not attach a timecounter when PM_TMR_LEN is 0. According to ACPI 6.2
section 5.2.9 ("Fixed ACPI Description Table (FADT)"), a value of zero here means that the PM timer is not supported.
Diffstat (limited to 'sys/dev/acpi/acpi_timer.c')
-rw-r--r--sys/dev/acpi/acpi_timer.c16
1 files changed, 14 insertions, 2 deletions
diff --git a/sys/dev/acpi/acpi_timer.c b/sys/dev/acpi/acpi_timer.c
index 774082e9da0..ae8414a1c61 100644
--- a/sys/dev/acpi/acpi_timer.c
+++ b/sys/dev/acpi/acpi_timer.c
@@ -1,4 +1,4 @@
-/* $NetBSD: acpi_timer.c,v 1.22 2013/12/27 18:51:44 christos Exp $ */
+/* $NetBSD: acpi_timer.c,v 1.23 2018/10/15 11:33:09 jmcneill Exp $ */
/*-
* Copyright (c) 2006 Matthias Drochner <drochner@NetBSD.org>
@@ -27,7 +27,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: acpi_timer.c,v 1.22 2013/12/27 18:51:44 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: acpi_timer.c,v 1.23 2018/10/15 11:33:09 jmcneill Exp $");
#include <sys/types.h>
#include <sys/systm.h>
@@ -52,6 +52,12 @@ static struct timecounter acpi_timecounter = {
NULL,
};
+static bool
+acpitimer_supported(void)
+{
+ return AcpiGbl_FADT.PmTimerLength != 0;
+}
+
int
acpitimer_init(struct acpi_softc *sc)
{
@@ -59,6 +65,9 @@ acpitimer_init(struct acpi_softc *sc)
uint32_t bits;
int i, j;
+ if (!acpitimer_supported())
+ return -1;
+
rv = AcpiGetTimerResolution(&bits);
if (ACPI_FAILURE(rv))
@@ -88,6 +97,9 @@ int
acpitimer_detach(void)
{
+ if (!acpitimer_supported())
+ return -1;
+
return tc_detach(&acpi_timecounter);
}